1. Field of the Invention
This invention relates to an apparatus for moving from position to position along coke ovens during the production of coke, and more particularly to a control system of such an apparatus for permitting the apparatus to stop accurately at the predetermined positions.
2. Description of the Prior Art
A coal charging car, a pusher, a coke guide car, and a coke quench car used in a coke retort or coke oven battery during the production of coke are required to stop at the exact position corresponding to each of the individual coke ovens. The allowable error in this instance is within about .+-.15 mm, which makes it difficult to operate these apparatus automatically. Accordingly, these apparatus are usually operated by an operator while visually confirming the stop positions.
Recently, a system for automatically controlling such an apparatus by a computer, which satisfies the requirements with respect to the strict allowable error, has been proposed and put into practically use. The computer used for such an automatic control is generally programmed so as to generate a stop command to a driving equipment of the apparatus when the apparatus reaches the position of predetermined distance in front of the position where the apparatus is to stop.
However, such an automatic control generally requires a fine adjustment for accurately stopping the apparatus at the predetermined stop positions, which is generally known as "inching operation", because :here is a significant variation of braking distance to completely stop the apparatus after generating stop command from the computer. The number of receptions of such an inching operation could be reduced if the running speed of the apparatus at the lower speed stage just before the generation of the stop command is decreased so that the variation of the braking distance may be minimized. However, his is disadvantageous in that the operating efficiency of the apparatus is significantly damaged.